Gap natural disturbance regime in the Castanopsis kawakamii forest
格氏栲林林窗自然干扰规律

This paper, through the study of the gap disturbanc e patterns in the forest, described some important characteristics related to th e disturbance regimes in Castanopsis kawakamii forest The results showed t hat the areas occupied by the expanded gaps (EG) accounted for 34 46% and by th e canopy gaps (CG) accounted for 17 81% of the total land areas in Castanopsi s kawakamii forest. The natural gap disturbance frequencies were 0.69% for EG and 0 36% for CG Per year, respectively, and the recovering i nterval of canopy gaps was about 281 a. Most EG size in Castanopsis kawakamii forest varied from 63 to 1257 m 2 with an average size of 244 m 2. Majori ty CG size in the forest varied from 22 to 707 m 2 with an average size of 126 m 2. The most effective way to form the gap patterns was the breakage of trun k and the standing die, and their proportions for all gapes existed were 36 22% and 32 28%, respectively. Large amount of gaps were formed by 1~5 gap makers, of which three gap maker gaps were the majority. However, most gaps were forme d 50 years ago, and most of which ranged from 10 to 40 years old. The gap distri bution patterns in the forest belonged to the uniform type. Major gap makers in the forest were Castanopsis kawakamii, Vaccinium mandarinorum, Lindera glauca and Tricalysia dubi with diameters below 60 cm. When the gap makers alloc ated in the canopy layer and the ground diameter was about 20~60 cm,the greater probability to make the gaps in the forest occurred.